The SS-Jagdverband Südost was formed from the Brandenburg unit Streifkorps Karpaten when it was transferred to the Waffen-SS in September 1944.
Jagdkommando Donau was a subunit of SS-Jagdeinsatz Ungarn made up of Waffen-SS and Kriegsmarine personnel. It was used in a failed attempt to float several barges of supplies through soviet held territory to the encircled German troops in Budapest.
The subunits of SS-Jagdverband Südost that were stationed in Yugoslavia was transferred to Austria were they joined the rest of of the unit in fighting the Red Army.

Commanders   

SS-Obersturmbannführer Benesch  (? 1944 - ?)
SS-Hauptsturmführer Alexander Auch  (? - ? 1944) (1)

Order of battle

SS-Jagdeinsatz Rumänien (SS-Hauptsturmführer Müller)
SS-Jagdeinsatz Kroatien (SS-Obersturmführer Schlau)
SS-Jagdeinsatz Bulgarien (SS-Obersturmführer Werg)
SS-Jagdeinsatz Ungarn (SS-Hauptsturmführer Wolfram Kirchner)
SS-Jagdeinsatz Donau (SS-Hauptsturmführer Primer)
- Leiter SS-Kampfschwimmergruppe :
-- 01.09.1944 - 00.03.1945 SS-Ustuf. Walter Schreiber
-- [SS-Kampfschwimmerschule : Dianabad, Wien (SS frogmen instruction course, Vienna]
SS-Jagdeinsatz Serbien Kdr. unknown)
SS-Jagdeinsatz Griechenland (Kdr. unknown)
SS-Jagdeinsatz Slowakei (Kdr. unknown)

Footnotes

1. Alexander Auch was a former "Brandenburger" Major.

Sources used

Kurt Mehner - Die Waffen-SS und Polizei 1939-1945
Antonio J. Munoz - Forgotten Legions: Obscure Combat Formations of the Waffen-SS

Reference material on this unit

Antonio J. Munoz - Forgotten Legions: Obscure Combat Formations of the Waffen-SS